Just because someone is smart enough to get into a leadership position doesn't mean that they act for the good. An essay on leadership written 20 years ago called "The Dark Side of Charisma" brought attention to the flawed types that do very well for themselves.
First there is the High Likeability Floater who rises to the top because they are liked by everyone and have no enemies but who avoids all difficult decisions.
Second we have the man who resents everything, who battles with everyone at least in their mind and who plots and manoeuvres around his colleagues most of whom are seen as enemies.
Lastly, there is the Narcissist whose confidence, energy and charm see them pulled up the ladder. They are awful managers because they don't believe they could possibly learn anything from anyone else.
People can train themselves by rehearsing speeches they feel employers want to hear and can practise psychometric tests to succeed in selection processes. The more they do this, the more their high performance becomes normal. Candidates can easily fake it and mask their true selves by paying for the 'best' education, changing their accent, dress code, and so on.
A person's height can even make a difference. The link between height and occupation has been studied since the early 20th century and evidence shows that taller people tend to work in more highly skilled occupations.
So don't beat yourself up about being a good player and not getting anywhere. The system is setup in such a way that true meritocracy in most organisations is extinct.